Comprehensive Analysis of the role of DIAPH3 in Cancers and Validation in Bladder Cancer

Abstract

Abstract Background Cancer is still a serious public health concern across the world at present. Previous studies have suggested that DIAPH3 might play a role in tumorigenesis and progression. However, the prognostic and immunological role of DIAPH3 in human cancers remains unclear. Method The TCGA, GTEx, TIMER2 and GEPIA2 database were utilized to investigate expression difference of DIAPH3 between normal tissues and cancers. For survival analysis, K-M plotter and Pronogscan website were employed. The genetic alteration analysis for DIAPH3 were conducted via cBioPortal database. The DIAPH3 related proteins were screened by the STRING website, and incorporated into KEGG and GO analysis using ‘clusterProfiler' package. Then, we used CIBERSORT algorithm to investigate the percentage of TIICs. For correlation analysis with molecular and immunological subtype, TMB, and MSI, the TISIDB database and SangerBox platform were utilized. To validate the function of DIAPH3 in BLCA, human bladder cancer cells T24 and 5637 were transfection by siRNA and Lipofectamine 8000. The efficiency of knockdown towards target gene was evaluated by qRT-PCR and Western Blot. The CCK-8 assays, clone formation assays, transwell, and wound healing assays were performed to test the proliferation, migration and invasion ability of cells. Results Various type of cancers had increased DIAPH3 expression than normal tissues, and DIAPH3 expression played an adverse prognostic role in most of cancers. Then, function analyses indicated that actin, microtubule and phagocytosis related pathways were enriched in DIAPH3 related proteins. DIAPH3 was strongly correlated to tumor immunity cells infiltration, especially MDSC. In addition, the link between DIAPH3 with immunological subtype, molecular subtype, TMB, and MSI were also observed. Furthermore, the knockdown of DIAPH3 could inhibit the proliferation, migration and invasion of bladder cancer cells. Conclusion In summary, our study demonstrated a correlation between DIAPH3 expression and prognosis, clinicopathological characteristics, immune infiltration cells, and immunotherapy response based on a pan-cancer analysis. The knockdown of DIAPH3 inhibited the proliferation, migration and invasion of bladder cancer cells. These findings might expand our knowledge of DIAPH3 as potential predictive biomarker or therapy target for cancers.